Railway vehicles for urban transport, such as tramway cars, stop along an elevated platform in order to allow passengers to enter and leave through lateral openings which are provided in the side of the vehicle and which are normally closed by doors.
A gap is provided between the side of the railway vehicle and the edge of the platform in order to allow the vehicle to move without colliding with the platform.
In order to prevent passengers who are entering or leaving the vehicle from falling or injuring themselves owing to the presence of this gap which they have to cross, it is known to provide for the openings for access to the vehicle to be equipped, in the lower portion thereof, with a door threshold which projects outwards relative to the side of the vehicle. This threshold fills, at least partially, the gap between the side of the vehicle and the platform at the location of the access opening, preventing passengers from injuring themselves.
Such a threshold also allows access to the vehicle for persons in wheelchairs or whose mobility is reduced, and ensures comfortable access for the other passengers.
These thresholds which project laterally out of the general space taken up by the vehicle can be caused, under some circumstances, to touch the edge of the platform.
Thus, there have been envisaged thresholds which can be deployed under the action of one or more actuators. These thresholds project relative to the side of the vehicle only when it is stopped along a platform. Conversely, the thresholds are retracted when the vehicle is moving. Such thresholds are very complex to produce and are therefore expensive.
Fixed thresholds which protrude permanently relative to the side of the vehicle have also been envisaged. In order to prevent these thresholds from touching the platform, they are arranged so as to be widely spaced from the edge of the platform so that a large gap still remains between the threshold and the platform. The problem of passenger safety is therefore overcome only in an incomplete manner.
So-called “breakable” thresholds have further been envisaged. These thresholds have elements for connection to the structure of the vehicle, which elements can break when the threshold comes into contact with the edge of the platform. The threshold, and in particular the connection means which it comprises, must be replaced after each breakage, which makes the cost of running the railway vehicle high.
Furthermore, these thresholds can be dangerous, after the connection elements have broken, because the threshold can then become completely or partially detached and injure a passer-by.